Metallocene-catalyzed polymers have been commercial for several years, and are used in many end-use applications, such as packaging, personal hygiene, automotive, flooring, adhesives, fibers, nonwovens, films, sheets, and fabrics.
Polymerization processes utilizing metallocene catalysts, including constrained geometry catalysts (CGC), to make polyolefin elastomers (POE) and/or polyolefin plastomers (POP) under reaction conditions that give high catalyst efficiency frequently become unstable. Modified methylalumoxane (MMAO3A), an impurity scavenger, is usually added in a fixed ratio to the CGC catalyst, and therefore, only a very small amount of MMAO3A is added under high efficiency, i.e. low catalyst level, conditions. Therefore, any variation in impurity levels in the feed during the polymerization process may cause a loss of reaction.
POE and POP polymerization processes exhibiting stability and/or efficiency over a range of feed impurity would be desirable.